The Z Sword (ゼットソード), or Zeta Sword in the English version of the Dragon Ball manga, is an ancient and extremely heavy sword that was embedded in the Z Sword Plateau at the Sacred World of the Kais.
The Z Sword looks like a hand-and-a-half sword. Judging by its thin cross-section and wide blade, it appears to be optimized for cutting as opposed to thrusting.
Once every 1,000 years, the Supreme Kais and the Gods of Destruction go to each other's realms and hold a coordination meeting. During one of these meetings, held roughly 75 Million Before Age, they got into an argument over some trifling thing and a certain short-tempered God of Destruction, Beerus, sealed Old Kai away inside the Z Sword as it would not have been proper for him to destroy the Sacred World of the Kais itself. As hard as they tried, none of the Kais that attempted to release the Z Sword were successful.
In Age 774, with Gohan needing medical attention, Shin brings him to the Sacred World of the Kais to heal as well as to try and release the Z Sword so as to gain access to its legendary power. Despite great difficulty and Kibito constantly decrying him for being a mere mortal, Gohan is successful in freeing the sword upon transforming into a Super Saiyan, stunning Kibito in the process. Though finding difficult to hold the sword due to its weight, Gohan begins training to wield it.
Later on when Goku visits the Sacred World of the Kais after returning to Other World, he tests Gohan by hurling a large boulder towards him, which the Z Sword cuts through easily. In order to test the sword's limits, Shin materializes a giant cube made of Katchin, the densest material in the universe, to give Goku to throw at Gohan. Unfortunately, the Z Sword breaks when attempting to slice through the cube. Despite Shin and Kibito expressing shock and great disappointment over this, not all hope was lost, as the breaking of the blade released the power held within the sword.In the future, Future Trunks trained with Shin and Kibito in preparation for Babidi's arrival. Trunks trained with the Z Sword and his power rose to new heights. When Trunks was battling against Future Dabura, Trunks used the sword as his weapon but was later spit on by Dabura, turning it into stone and it broke after Trunks let go of it. The power sealed within the sword would be lost forever.
Video game appearances
The Z Sword appears in the story mode of Dragon Ball Z: Legendary Super Warriors and Dragon Ball Z: Buu's Fury. In Dragon Ball Z: Budokai Tenkaichi 3, one of the mini-games that appear while the game is loading, involves Gohan pulling out as many Z Swords as he can. In Dragon Ball Z: Tenkaichi Tag Team, Gohan can be seen wielding the Z Sword in the background of Training Mode.
In the game Dragon Ball Z: Shin Budokai - Another Road, Gohan and Shin go to the Sacred World of the Kais to release the Z Sword only to find that Gohan cannot remove it, resulting in their need of the "chosen one". The "chosen one" turns out to be the Future Gohan, who proceeds to remove the sword easily. The sword can be seen in the game as a projectile attack used by both Gohan and Future Gohan while using Old Kai's Unlock Ability. Ultimate Gohan can also use his Z Sword in several attacks.
In Dragon Ball Z: Supersonic Warriors 2, Gohan has a team attack with Future Trunks, titled Twin Sword Slash, in which he uses the Z Sword. The Z Sword is one of the two swords Ultimate Gohan can use in Super Dragon Ball Z, the other one being his training sword. Ultimate Gohan (Z Sword) also uses the sword in Dragon Ball Heroes, notably as part of a super attack called Z Sword Slash (ゼットソードスラッシュ).
In Dragon Ball Z: Battle of Z, the Z Sword appears as a card that can be equipped onto a character. Its positive effects raise the character's melee and ki blast attack power greatly, while its negative effects prevent the character from evading. The Z Sword card is an absolute rare, and appears occasionally in subsequent weekly card releases.
"A replica of a legendary sword from the Kais' world. Gives great power to anyone who draws it."
"A long time ago, I was trapped inside a sword known as the Z Sword. It was Lord Beerus who put me in there. Every thousand years, the Supreme Kais and the Gods of Destruction hold a meeting. And we had a teensy disagreement... It all happened so fast... Once I realized what happened, I was already inside of the sword. That was about 75 million years ago, I think... I had nothing but free time. Nothing! I know that Lord Beerus was simply doing what he does, but I want my glorious youth back! Hm? What did we argue about? Hmm... I can't seem to remember."
— Elder Kai telling how he was sealed in Xenoverse 2
In Dragon Ball Xenoverse 2, the Z Sword returns as an equipable accessory. After Towa fails to appear in Age 779 after tricking Beerus and Whis by hacking the Time Nest communications and pretending to be Chronoa to lure him and Whis away, Whis suggests sealing Elder Kai as a way for Beerus to vent his anger but Elder Kai protests causing Whis to suggest he spar with Beerus and the Future Warrior. Afterwards as Whis & Beerus are about to leave Elder Kai reveals he still holds a slight grudge over being sealed, though Beerus manages to hear his grumbling and warns him that he can hear him, though decides to not to seal Elder Kai. After Whis and Beerus leave following the sparring session, the Future Warrior can talk to Elder Kai who will tell them how he came to be sealed within the sword. Interestingly, he reveals he had forgotten what the disagreement between him and Beerus was about.
- The legend of the Z Sword mirrors the Arthurian legend of the Sword in the Stone, with it also being incredibly hard to pull out and it later being broken, however the difference is that Gohan does not immediately take a higher position upon pulling the sword, obviously (i.e. a Supreme Kai), as Arthur had upon pulling the Excalibur (as the sword is called in the story) out from the stone with relative ease, as according to the story, the one pulling the legendary sword with all his might out of its pedestal would be immediately crowned the rightful King of England.
- The name "Zeta Sword" used in the English manga matches the Greek pronunciation for the letter Z, "Zeta".
- In the English Dragon Ball Super manga, the sword is named the Z Sword.